What is the C# Mathf.Lerp equivalent in Python?
Lerp typically means linear interpolation.

Assume A, B, C are floating point values.

Assume C is in the range [0.0, 1.0] 

lerp(A, B, C) might be implemented as

value = (C * A) + ((1-C) * B) // convex combination

When C equals 0 value equals B.

When C equals 1 value equals A.

When C equals .5 value equals the average of A and B.

Of course you can switch the factors (C) and (1-C) depending on your desired implementation.  You can also switch A and B depending on your desired implementation.